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"This paper presents the results of an experimental study of the behavior of steel fiber high strength concrete confined by hoops round cross-section. Behavior strength and energy absorption capability of confined fibrous concrete is the main focus in this study. Fibrous concrete test specimens are made by varying the concrete compressive strength, characteristics of confining reinforcement that is volumetric ratio and spacing. All these specimens use longitudinal reinforcement with the same ratio. Experimental results shows that the strength enhancement of confined steel fiber concrete is strongly influenced by the characteristics of the installed confining reinforcement. Stress-strain behavior of confined steel fiber high strength concrete between predictions based on existing confinement models with experimental results differ significantly, especially in the post-peak behavior. Therefore, prior modifications or developed the confinement model in order to obtain predictions of the behavior of confined steel fiber high strength concrete accurately."

"[Produksi biogas menggunakan limbah cair kelapa sawit (LCKS) dengan prosesdigesting anaerob menggunakan tangki digester menghasilkan CH4 sebesar ±87% dangas CO2 sebsar ±13%. Metode absorpsi dan kolom adsorpsi adalah beberapa prosessederhana yang mudah untuk diaplikasikan, aplikasinya dapat menggunakan zeolitalam sebagai adsorben dan larutan Ca(OH)2 sebagai absorben. Kedua metode tersebutdapat digunakan secara simultan untuk proses purifikasi biogas dengan cara biogasdialirkan terlebih dahulu ke dalam larutan Ca(OH)2 dan kemudian akan dilewatkan kedalam kolom dengan ukuran tinggi dan diameter dalam sebesar 15cm dan 0,8cm yangberisi zeolit alam termodifikasi. Untuk meningkatkan daya adsorpsi dapat dilakukanmodifikasi permukaan zeolit alam dengan perlakuan asam kuat-basa kuat denganvariasi konsentrasi 1, 2, dan 3M, kalsinasi pada suhu 450°C, dan melapisi permukaanzeolit alam dengan beberapa variasi konsentrasi kitosan yaitu 0,25; 0,5; dan 1%.Penggunaan asam kuat-basa kuat dapat meningkatlkan luas permukaan dan diameter,sedangkan pelapisan kitosan dapat meningkatkan kapasitas adsorpsi pada zeolit alamkarena adanya gugus amine pada kitosan. Hasil modifikasi dan aktivasi zeolit akandiuji menggunakan SEM-EDX, BET, FTIR, dan XRD, sedangkan hasil purifikasibiogas akan diuji menggunakan gas chromatography (GC). Adsorben terbaik yangdidapatkan dari penelitian ini adalah adsorben dengan perlakuan asam-basa 2M yangkemudian dilapisi kitosan 0,5%. Hasil purifikasi yang didapatkan adalah pengurangankadar CO2 pada biogas menjadi 0.42% dan peningkatan kadar CH4 menjadi 99.58%.;Production of biogas from POME by anaerobic digestion process using digester has been shown able to produce CH4 87 and CO2 13 The methods of absorption and adsorption is simple to be applied this method can be done with zeolite as adsorbent and Ca OH 2 as absorbent Both methods can be applied simultaneous for purification which the gas will pass through the chamber Ca OH 2 solution and then passed the column filled with modified natural zeolite Enhancing the adsorption capability done with modified the zeolite using some concentration in strong acid base 1 2 and 3M calcination at 450 C and coating with chitosan 0 25 0 5 and 1 Usage of strong acid and strong base can increase the surface area and diameter of the zeolite pores while coating with chitosan can increase the adsorption capacity because the amine functional group from chitosan The result of the modification of zeolite will be tested with SEM EDX BET FTIR and XRD while the result of the purification will be characterized with GC The best adsorbent from this research is zeolite modified with acid base 2M and coated with 0 5 of chitosan The final result from this research is CO2 about 0 42 and the CH4 become 99 58 , Production of biogas from POME by anaerobic digestion process using digester has been shown able to produce CH4 87 and CO2 13 The methods of absorption and adsorption is simple to be applied this method can be done with zeolite as adsorbent and Ca OH 2 as absorbent Both methods can be applied simultaneous for purification which the gas will pass through the chamber Ca OH 2 solution and then passed the column filled with modified natural zeolite Enhancing the adsorption capability done with modified the zeolite using some concentration in strong acid base 1 2 and 3M calcination at 450 C and coating with chitosan 0 25 0 5 and 1 Usage of strong acid and strong base can increase the surface area and diameter of the zeolite pores while coating with chitosan can increase the adsorption capacity because the amine functional group from chitosan The result of the modification of zeolite will be tested with SEM EDX BET FTIR and XRD while the result of the purification will be characterized with GC The best adsorbent from this research is zeolite modified with acid base 2M and coated with 0 5 of chitosan The final result from this research is CO2 about 0 42 and the CH4 become 99 58 ]"

"Perhitungan sifat optik material berupa absorpsi atau penyerapan cahaya pada semikonduktor sering dilakukan dengan menggunakan asumsi dispersi energi kuadratik (parabola) di kedua pita energi valensi dan konduksi. Namun, pendekatan tersebut tidak cukup realistis, mengingat bentuk pita energi yang kita temui pada material tidak selalu mengikuti pendekatan kuadratik. Oleh karena itu, pada penelitian kali ini, kami menyelidiki pengaruh dari beberapa bentuk pita energi pada penyerapan cahaya di material semikonduktor. Secara khusus, spektrum penyerapan cahaya dihitung untuk material semikonduktor hipotetis dengan bentuk pita energi kuadratik (parabolik) dan nonparabolik seperti kuartik (pangkat empat) dan sekstik (pangkat enam). Kami juga mempertimbangkan efek dimensi material (dari satu hingga tiga dimensi) lalu membandingkan hasil yang telah dihitung. Untuk mendukung model tersebut, kami kemudian menghitung penyerapan cahaya secara numerik menggunakan pendekatan density functional theory (DFT) dari beberapa representasi material yang kami temukan memiliki bentuk dispersi energi yang serupa dengan yang model yang diajukan, seperti PtS2 dan GeTe. Kami menemukan dalam semikonduktor hipotetis untuk perhitungan sepasang pita energi yang sama, efek dimensi memengaruhi hasil penyerapan cahaya, semakin tinggi dimensinya, semakin tinggi penyerapan cahaya yang kami dapatkan. Untuk perhitungan pita kombinasi, tidak hanya dimensi yang memengaruhi absorpsi, tetapi juga bentuk pita konduksi dan pita valensinya. Kami menemukan bahwa material PtS2 memiliki hasil yang mirip dengan penyerapan cahaya untuk kombinasi pita nc = 2 dan nv = 4. Dan untuk GeTe kami menemukan bahwa hasilnya berbeda dengan kombinasi nc = 2 and nv = 4.

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Calculations of optical properties such as the light absorption of semiconductors are often performed by assuming parabolic energy dispersion of both valence and conduction energy bands. However, this approach is not quite realistic, because the actual shape of the energy bands often deviates from the quadratic shape. Therefore, we need to investigate the effect of a more realistic shapes of electronic band structures on light absorption in semiconducting materials. In this study, the absorption spectra are calculated for hypothetical semiconductors with higher degree polynomial, i.e. quartic (fourth-degree polynomial) and sextic (sixth-degree polynomial) energy dispersion. We also consider one to three dimensional cases and compare the calculated spectra. To validate our model, the calculated spectra are compared with some representative materials having similar band shapes, such as Si, PtS2, and GeTe. In this case, the light absorption is calculated numerically using a first-principles, density functional theory approach. We found in the hypothetical semiconductor for band pair transition, its dimension affects the light absorption. Higher dimensions have larger light absorption. The calculations also show that the transition between bands is affected by not only the material’s dimension, but also the shape of the conduction band and valence band. We found that the light absorption of material PtS2 is similar to the calculated light absorption that corresponds to a transition of band nc = 2 to nv = 4. Meanwhile, GeTe’s light absorption deviates from such an optical transition."

"Disperse Red 1 (DR 1) adalah pewarna merah yang memiliki unsur kimia C16H18N4O3. DR 1 merupakan pewarna azo yang mempunyai sifat fotoisomerisasi reversibel. Pada pewarna azo perubahan dari trans ke cis dapat menyebabkan perubahan reversibel yang diinduksi cahaya pada beberapa pewarna, seperti DR 1. Perubahan struktur dari trans ke cis terjadi karena penyerapan cahaya ultraviolet (UV). Pada penelitian ini dilakukan dengan tujuan untuk mengetahui nilai spektrum serapan cahaya pada perubahan struktur molekul Disperse Red 1 isomer trans terhadap isomer 90° dan isomer cis, sehingga mengetahui besar pergeseran spektrum penyerapan cahaya karena penyerapan UV menggunakan metode komputasi density functional theory (DFT). Hasil analisa berdasarkan spektrum serapan optik didapatkan perubahan warna pada isomer trans, 90°, dan cis karena ketika trans menyerap sinar UV maka akan terjadi pergeseran molekul sehingga membentuk isomer 90° dan isomer cis, pada saat pergeseran inilah molekul menyerap energi cahaya sehingga mengalami perubahan warna.

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Disperse Red 1 (DR 1) is a red dye with the chemical element C16H18N4O3. DR 1 is an azo dye with reversible photoisomerisation properties. Some azo dyes, including DR 1, undergo light-induced reversible transitions from trans to cis. Changes in structure from trans to cis occur due to ultraviolet (UV) light absorption. This study aimed to determine the value of changes in the molecular structure of Disperse Red 1 trans isomer to 90° isomer and cis isomer, on the light absorption spectrum in order to determine the magnitude of the shift in the light absorption spectrum due to UV absorption using the density functional theory (DFT) computational method. Based on the optical absorption spectrum, the analysis revealed colour changes in the trans, 90 °, and cis isomers. When the trans-absorbed UV light, a molecular shift occurred to form the 90° isomer and the cis isomer. The molecule absorbed light energy during this shift, causing it to change colour."

"Sintesis dan karakterisasi material MoS2 telah dilakukan melalui metode hidrotermal menggunakan prekursor sodium molybdate dihydrate dan thiourea. Penelitian ini bertujuan untuk mendapatkan MoS2 dengan konsentrasi prekursor yang optimal diantara variasi prekursor 0,25 M; 0,5 M; 1,0 M; dan 1,5 M sehingga dapat menyerap gelombang mikro pada kisaran X-band secara efektif. Konsentrasi prekursor MoS2 divariasikan menjadi 0,25 M; 0,5 M; 1,0 M; dan 1,5 M disintesis dengan suhu reaksi 2000 C selama 24 jam. Karakterisasi MoS2 yang telah disintesis dilakukan dengan alat X-Ray Diffraction (XRD) untuk analisis fasa, Scanning Electron Microscopy – Energy Dispersive X-Ray Spectroscopy (SEM-EDS) untuk mengetahui morfologi yang terbentuk, Particle Size Analyzer (PSA) untuk mengetahui ukuran partikel, dan Vector Network Analyzer (VNA) untuk mengetahui kemampuan material dalam menyerap gelombang mikro. Dari hasil penelitian diperoleh MoS2 single phase dengan struktur heksagonal space group P63/mmc, memiliki morfologi nanosheet microsphere, memiliki ukuran partikel pada interval 138,3 hingga 189,6 nm, dan memiliki besar Reflection Loss sebesar -18,79 dB untuk konsentrasi 0,25 M; -19,6 dB untuk konsentrasi 0,5 M; -23,06 untuk konsentrasi 1,0 M; dan -24,23 untuk konsentrasi 1,5 M. Reflection Loss terbaik mencapai −24,23 dB pada frekuensi 10,34 GHz diperoleh saat konsentrasi prekursor MoS2 sebesar 1,5 M. Maka dapat disimpulkan bahwa konsentrasi prekursor MoS2 yang disintesis secara hidrotermal yang optimal diantara 0,25 M; 0,5 M; 1,0 M; dan 1,5 M adalah 1,5 M, dikarenakan kemampuannya menyerap gelombang mikro hingga 99,62% pada frekuensi 10,34 GHz.

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Synthesis and characterization of MoS2 has been done through hydrothermal method with Sodium Molybdate Dihydrate and Thiourea as precursors. This research is done to obtain MoS2 with the optimal concentration among the precursor variations of 0.25 M; 0.5 M; 1.0 M; and 1.5 M to improve its ability to microwave absorption on the X-band. The 0.25 M, 0.5 M, 1.0 M and 1.5 M concentrations of the MoS2 is synthesized at temperature of 2000 C for 24 hours. The measurements that have been done to the sample are XRD for phase analysis, SEM-EDS for morphology identification, PSA to obtain particle size and VNA to identify the sample's microwave absorption abilities. Yielded results concluded that MoS2 single phase with a hexagonal structure and space group P63/mmc, has a nanosheet microsphere morphology, has a particle size in the interval of 138.8 to 189.6 nm, and has a Reflection Loss of -18.79 dB for concentration 0.25 M; -19.6 dB for a concentration of 0.5 M; -23.06 for a concentration of 1.0 M; and -24.23 for a concentration of 1.5 M. The best Reflection Loss reached -24.23 dB at a frequency of 10.34 GHz obtained when the precursor concentration of the MoS2 was 1.5 M. It can be concluded that the optimal precursor concentration of the hydrothermally synthesized MoS2 between 0.25 M; 0.5 M; 1.0 M; and 1.5 M is 1.5 M, due to its ability to absorb microwaves up to 99.62% at a frequency of 10.34 GHz."

"Keamanan pada kendaraan merupakan aspek penting yang harus diperhatikan dalam perancangan dan pengembangan sebuah kendaraan. Saat terjadi kecelakaan, keamanan pada pengendara sangat dipengaruhi oleh rancangan struktur kendaraan. Kemampuan mengamankan pengendara oleh struktur ini dapat disebut sebagai crashworthiness. Metode pengujian Crashworthiness dilakukan untuk mengevaluasi desain struktur kendaraan yang berdeformasi, berdasarkan parameter energy absorption dan efisiensi gaya tumbukan-nya. Mayoritas kecelakaan lalu lintas melibatkan tabrakan pada arah depan kendaraan, membuat struktur bumper kendaraan menjadi bagian penting, serta didesain spesifik untuk berdeformasi sehingga dapat menyerap energi kinetik tumbukan secara efektif dan mengurangi penyebaran energi yang dapat mempengaruhi pengguna dan struktur lain kendaraan. Variasi geometri struktur dikembangkan dengan menambahkan crush initiator sehingga mempengaruhi karakteristik struktur dalam menyerap energi kinetik. Tujuan dari penelitian ini untuk mengetahui performa crashworthiness dari desain struktur Tabung berdinding tipis dengan penambahan crush initiator berupa bentuk corrugated pada sisi tabung. Pengujian pembebanan kuasi static dan dinamik menggunakan metode simulasi dengan software Ansys-LS DYNA. Hubungan variasi jumlah crush initiator dan ketebalan tabung diteliti untuk mengetahui pengaruhnya terhadap struktur sehingga didapat desain dengan performa crashworthiness terbaik. Pada metode ini, didapatkan bahwa pilihan variasi spesimen terbaik adalah C2T2 dengan EA 188,81 J, SEA 743,23 J/kg, dan CFE sebesar 76,29%. Lalu disusul dengan C3T1 dengan EA sebesar 84,26 J, SEA sebesar 705,61 J/kg, dan CFE sebesar 67,03%. Hal ini juga dapat menandakan bahwa banyaknya tumpukan memengaruhi performa penyerapan energi. Namun sisi yang kurang baik pada hasil tersebut adalah nilai Pmax yang masih cukup tinggi dan belum terdapat inkonsistensi dalam hasil penambahan variasi struktur

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Vehicle safety is an important aspect that must be considered in the design and development of a vehicle. When an accident occurs, the safety of the driver is greatly influenced by the design of the vehicle structure. The ability to secure the rider by this structure can be referred to as crashworthiness. The Crashworthiness test method was carried out to evaluate the design of the deformed vehicle structure, based on the energy absorption parameters and the efficiency of the impact force. The majority of traffic accidents involve collisions at the front of the vehicle, making the vehicle bumper structure an important part, and specifically designed to deform so that it can absorb the kinetic energy of the collision effectively and reduce the spread of energy that can affect the user and other structures of the vehicle. Variations in the geometry of the structure are developed by adding a crush initiator so that it affects the characteristics of the structure in absorbing kinetic energy. The purpose of this study is to determine the crashworthiness performance of the thin-walled tube structure design with the addition of a crush initiator in the form of a corrugated form on the side of the tube. Testing of quasi-static and dynamic loading using simulation method with Ansys-LS DYNA software. The relationship between variations in the number of crush initiators and tube thickness was investigated to determine the effect on the structure so that the design with the best crashworthiness performance was obtained. In this method, it was found that the best choice of specimen variation was C2T2 with EA 188.81 J, SEA 743.23 J/kg, and CFE at 76.29%. Then followed by C3T1 with EA of 84.26 J, SEA of 705.61 J/kg, and CFE of 67.03%. It can also indicate that the number of stacks affects the energy absorption performance. However, the bad side of these results is the Pmax value which is still quite high and there is no inconsistency in the results of adding structural variations."

"Penggunaan manufaktur Aditif telah dikembangkan dalam teknologi baru dan canggih untuk memproduksi dan mengembangkan produk dari prototipe hingga produk sebenarnya, hal ini telah merevolusi industri manufaktur. Dalam kelayakan tabrakan, energi tumbukan pada awalnya dan sebagian besar diserap oleh crash box. Hal ini dapat diuji secara eksperimental dan simulasi menggunakan software LS-DYNA. Tingkat ketebalan Honeycomb telah diteliti dan dikatakan dapat meningkatkan penyerapan energi secara keseluruhan, meskipun penelitian eksperimental ekstensif belum dilakukan. Berdasarkan hasil, menarik perhatian bahwa temuan kami pada percobaan dan hasil simulasi menunjukkan perbedaan dalam hal variasi Honeycomb mana yang memiliki penyerapan energi tertinggi, simulasi menunjukkan peningkatan penyerapan energi secara bertahap dari Ketebalan seragam, Ketebalan bergradasi, dan ketebalan bergradasi fungsional dengan hasilnya masing-masing 0,43 Joule, 0,68 Joule dan 0,87 Joule. Sedangkan percobaan menunjukkan urutan tertinggi hingga terendah sebagai Ketebalan bergradasi, Ketebalan Seragam, ketebalan bergradasi fungsional dengan hasil masing-masing 0,78 Joule, 0,47 Joule, dan 0,45 Joule.

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The use of Additive manufacturing has been developed in new and advanced technologies to manufacture and develop products from a prototype to actual products, this has revolutionized the manufacturing industry. In crashworthiness, the impact energy is initially and mostly absorbed by the crash box. This can be tested experimentally and by simulation using LS-DYNA software. Graded thickness Honeycomb has been researched and said to improve on the overall energy absorption, though extensive experimental research has not been done. Based on results, has caught the interest that our findings of the experiment and simulation results shows difference in terms of which Honeycomb variation has the highest Energy absorption, the simulation shows gradual increase of energy absorption from Uniform thickness, Graded thickness and functionally graded thickness with a result 0.43 Joules, 0.68 Joules and 0.87 Joules respectively. Whereas the experiment shows the order in highest to lowest as Graded thickness, Uniform Thickness, functionally graded thickness with a result 0.78 Joules, 0.47 Joules and 0.45 Joules respectively."

"Background: Starfruit (Averrhoa carambola) leaves contain flavone derivatives that exhibit anti-hyperglycemiceffects. This study aims to determine the effect of starfruit leaves in reducing glucose absorption in intestinal epithelialcells of mice. Methods: This study was done by performing perfusion on the small intestines of mice. The mice thatwere used in this study were divided into four groups. The control group was given glucose solution without infusedstarfruit leaves whereas, the remaining 3 groups were given 3 mmol (540 mg/dL) glucose solution with infused starfruitleaves of varying concentrations; 200, 400, and 600 mg/kg. Samples were collected at 0, 15th, 30th, 45th, and 60th minute.The sample was tested for glucose levels using spectrophotometry. Results: Test of significance showed a significantdifference between the control group and the test group with p < 0.05. Conclusions: Starfruit leaves have a reductioneffect towards glucose absorption in the small intestines in Wistar strains where the group using 600 mg/kg of infusedstarfruit leaves have the most significant effect as compared to other groups."